Hermetically sealed condenser



July 14, 1936. 1.. KOPINSKI 2,047,273

HERMETICALLY SEALED CONDENSER Filed Nov. 6, 1953 I I l I l I I I I I l I I I I|I |l ll| Patented July 14, 1936 oars Ta FFiC Y 2,04%273 HERMETICALLY SEALED CONDENSER Louis Kopinski, Cicero, 111., assignor to John E. Fast & Company, Chicago, 111., a. corporation of Illinois An object of this invention is to provide an enclosure for a paper wound condenser element which is air and moisture proof, and which is simple and inexpensive to make and to assemble.

This and other objects, as will hereinafter appear, are accomplished by this invention which is fully described in the following specification and shown in the accompanying drawing, in which- Figure 1 is a perspective view of a condenser made according to this invention;

Fig. 2 is an enlarged longitudinal section through the enclosure for the condenser;

Fig. 3 is a transverse section on the line 33 of Fig. 2;

Fig. 4 is a vertical section through a treating tank showing a series of condensers duringthe process of being heated and exhausted;

Figs. 5 and 6 are sections similar to Fig. 2 show ing modified forms of the enclosure for the condenser.

The embodiment illustrated in Figs. 1 to 3 comprises a paper wound condenser A of any well known type having wire leads in, I I, extending preferably substantially axially from its two ends. When the condenser A has been wound it is placed in a hollow tube l2 which is preferably of glass, but which may be made of porcelain, or of Isolantite, if these materials can be secured with a non-porous structure, or it may be made of Bakelite. The two ends of the tube l2 are preferably provided with outwardly extending beads l3 and gaskets I4 of paper or cork, and are adapted to bear against the ends of the lass tube.

A cap l5 of suitable metal, as brass, steel, zinc or the like, encloses the gasket and has an inwardly extending flange [5. The gasket is provided with a central hole 16 through which the wires '10, H pass. At the same time the cap is provided with a similar hole I! through which passes the wires H), II. Having assembled the gasket and cap over each end of the condenser. pressure is brought to bear on the ends of the caps, thereby forcing the gaskets l4 tightly into contact with the beaded ends of the tubes. While so held the cap I5 is rolled or pressed inwardly at I5 to firmly grip the inner surface of the bead l3, thereby securely locking the cap on the tube and holding the gasket I 4 firmly against the end of the tube so as to insure that no air or moisture will pass the gasket even afterthe pressure is removed from the caps. Solder is now applied to one of the holes as l1 (Fig. 2) while the opposite opening l1 remains open while the con:- denser is heated, exhausted and filled with oil as will be explained.

Having assembled a number of the condensers in the form shown in Fig. 2, they are placed on end in a treating and impregnating tank B, as shown in Fig. 4, with the unfilled openings l1 uppermost. This tank is provided with a steam jacket l8 to which steam is supplied from a suitable source through a pipe l9. The tank has a cover 20 whichis secured thereon by means of interior of the tank particularly to see the level of the oil supplied thereto, as will presently be explained.

A pipe 24- connects the tank with a suitable means for exhausting gases therefrom, and is controlled by means of a valve 25. A pipe 26 controlled by a valve 21 connects with a suitable sup: ply of insulating oil of the type which is suitable for filling condensers. A pipe 28 controlled by a valve 2S serves for withdrawing oil from the tank B after the condensers have been filled.

After a number of condensers have been assembled and placed in the treating tank B, as shown in Fig. 4, with the unsoldered opening I! at the top, the tank is heated by means of steam supplied to the steam jacket of the tank through the pipe l9, and the tank is then. heated to a temperature of about 240 F. and held at this temperature for about one hour where small condensers oi the size and type herein contemplated are to be treated. .At the end of one hour the valve is opened and a vacuum is gradually applied to the condenser, after which the vacuum is raised to a vacuum of about one millimeter of mercury. This degree of vacuum and a temperature of about 240 is then maintained for a period of about six hours. The temperature within the tank is then reduced to about 180 F. and a suitable oil 30 is introduced through the pipe 26, the oil preferably having been previously preheated to 180 F. This temperature and a vacuum of about one millimeter of mercury is then maintained for about two hours.

At the end of this time the temperature is permitted to drop to about 100 F., after which the vacuum is released and the valve 29 opened so as to drain of! the excess oil through the pipe 28. The condensers are then removed from the tank. Each condenser is now filled with oil, the oil having passed in through the unsoldered opening I! as soon as the level of the oil is raised above that of this opening. The previous exhausting had removed substantially all the gas and vapor from these tubes, so that the oil will readily pass through the opening l1, thereby filling the condenser and the voids between the layers of paper and metal foil.

Upon removing the-condenser from thetank a drop of solder is immediately applied to the opening I! so as to completely close the opening, thereby hermetically sealing the condenser against air and moisture." Great care must be taken, however, that none 01' the oil within the condenser is spilled during the operation of removing from the tank previous to soldering.

The reason for permitting these condensers to cool whilestill below the surface of the oil 30 is that it is desirable that no vacuum bubbles be formed within the condenser as would be the case if they were to be sealed shut while the oil is too hot. The coeflicient of expansion of this insulating oil is quite high and the tubes and caps here usedare quite rigid and unyielding. Consequently, a vacuum without air spaces is formed within the tube. Thus it will be seen that a very simple and desirable form of condenser is provided, and one which can be efiiciently manufactured.

In Fig. 5 is shown a modified form of the invention in which the tube H2 is provided with screw threads H3 at its ends, which are adapted to be engaged with the correspondingly threaded ends 5 of the caps H5. A gasket H4 is held in place against the end of the tube at each end by the cap. The cap and gasket are provided with openings as before for the wires H0, il l, and each wire is soldered in the opening in the cap as has previously been explained for the condenser of Fig.2, this condenser having been heated, exhausted and supplied with oil in the same Way. This cap is preferably cemented on to prevent removal and to further insure an airtight joint.

In Fig. 6 is shown another modified form of the invention in which a tube 2I2, preferably of the same inside and outside diameter throughout, has metal caps 2l5 secured over its two ends by means of a layer of a cement 2l6, such asvarnish, shellac, or other suitable cementitious material that will make an air-tight joint. This condenser will then have the wire at one end soldered, and will be placed in an impregnating tank and heated and exhausted and filled with a suitable oil, after which the hole at the opposite end of the condenser will be soldered shut, as previously described.

The times given above for heating, exhausting and impregnating the condensers in the tank are based on small condensers. For larger condensers, these periods would have to be increasedperhaps doubled.

While I have shown and described but a few embodiments of my invention, it is to be understood that it is capable of many modifications. Changes, therefore, in the construction and arrangement may be made which do not depart from the spirit and scope of the invention as disclosed in the appended claims.

I claim:-

1. In a condenser, a wound condenser element composed of alternate layers of paper and metal foil and having a metal lead extending from each end, an electrical insulating tube surrounding the element, a metal cap secured on the tube at each end and having an opening through which extends one of said metal leads, each metal lead being tightly soldered to the cap through which it passes, the whole being hermetically sealed, and oil filling substantially all voids within the tube and condenser element so as to exclude air and moisture.

2. In a condenser, a wound condenser element composed of alternate layers of paper and metal foil and having a metal 'lead extending from each end, an electrical insulating tube surrounding the element, a metal cap secured on the tube at each end and having an opening through which extends one of said metal leads, a gasket within each cap bearing against the end of the tube, each metal lead being tightly soldered to the cap through which it passes, the whole being hermetically sealed, and oil filling substantially all voids within the tube and condenser element so as to exclude air and moisture.

3. In a condenser, a wound condenser element composed of alternate layers of paper and metal foil and having a metal lead extending from each end, an electrical insulating tube surrounding the element, a metal cap secured on the tube at each end and having an opening through which extends one of said metal leads, a gasket within each cap bearing against the end of the tube, each metal lead being tightly soldered to the cap through which it passes, the whole being hermetically sealed, and oil filling substantially all voids within the tube and condenser element so as to exclude air and moisture, the interior of the tube being under a vacuum so that the caps are pressed against the gaskets by atmospheric pressure.

4. In a condenser, a wound condenser element composed of alternate layers of paper and metal foil and having a metal lead extending from each end, a glass tube surrounding the element, a metal cap secured on the tube at each end and having an opening through which extends one of said metal leads, a gasket within each cap bearing against the end of the tube, each metal lead being tightly soldered to the cap through which it passes, the whole being hermetically sealed, and oil filling substantially all voids within the tube and condenser element so as to exclude air ,5

and moisture.

5. In a condenser, a Wound condenser element composed of alternate layers of paper and metal foil and having a metal lead extending from each end, a glass tube surrounding the element and having an enlarged bead at each end, a metal y cap surrounding each end of the tube and having an opening through which extends one of said metal heads, a gasket between each cap and each end of the tube, the cap extending over the bead and being deformed therearound to hold the gasket tightly over the end of the tube, each metal lead being tightly soldered to the cap through which it passes, the whole being hermetically sealed, and oil filling substantially all voids within the tube and condenser element so as to exclude air and moisture.

6. The method of making condensers comprising rolling a condenser body with alternate layers of metal foil and flexible dielectric, the condenser body having a metal lead extending axially from each end, enclosing said condenser body in a tube of dielectric material, passing the metal leads through holes in metal caps, securing one of said metal caps over each end of the tube, soldering one of said leads in its cap to seal the same, placing a plurality of said condensers in a vessel with the unsoldered caps uppermost, heating and simultaneously exhausting the vessel for a considerable period of time, introducing a suitable insulating oil to the vessel to completely submerge the condensers without releasing the vacuum, continuing the heating at a lower temperature and the vacuum for a period of several hours, cooling and removing the vacuum, while the condensers are submerged, and soldering the lead in the unsoldered cap to hermetically seal the condenser.

LOUIS KOPINSKI. 

